<?php
/**
 * Bounded asynchronous cloud run polling.
 *
 * @package TwoUA_SEO_Release_Guard
 */

declare(strict_types=1);

namespace TwoUA\SeoReleaseGuard;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

final class RunPoller {
	public const CRON_HOOK      = 'two_ua_release_guard_poll';
	private const MAX_POLLS     = 60;
	private const RETRY_SECONDS = 60;

	private RunApiClient $client;
	private RunResultStore $results;
	private PairingService $pairing;

	public function __construct( RunApiClient $client, RunResultStore $results, PairingService $pairing ) {
		$this->client  = $client;
		$this->results = $results;
		$this->pairing = $pairing;
	}

	public function register_hooks(): void {
		add_action( self::CRON_HOOK, array( $this, 'poll' ), 10, 2 );
	}

	public function start( RunSummary $summary ): void {
		$this->results->save( $summary );
		if ( ! $summary->is_terminal() ) {
			$this->schedule( $summary->state->public_id, 0, $summary->next_polling_delay );
		}
	}

	public function poll( string $public_id, int $attempt = 0 ): void {
		if ( ! $this->pairing->is_connected() || $attempt >= self::MAX_POLLS ) {
			return;
		}

		try {
			$summary = $this->client->status( $public_id );
			$this->results->save( $summary );
			if ( ! $summary->is_terminal() ) {
				$this->schedule( $public_id, $attempt + 1, $summary->next_polling_delay );
			}
		} catch ( ApiException $exception ) {
			$this->results->mark_error( $exception->error_code() );
			if ( ApiException::REMOTE_FETCH === $exception->error_code() ) {
				$this->schedule( $public_id, $attempt + 1, self::RETRY_SECONDS );
			}
		}
	}

	private function schedule( string $public_id, int $attempt, int $delay ): void {
		if ( $attempt >= self::MAX_POLLS ) {
			return;
		}

		wp_schedule_single_event(
			time() + max( 5, min( 300, $delay ) ),
			self::CRON_HOOK,
			array( $public_id, $attempt )
		);
	}
}